Things You'll Need
- Small (10 gallon) breeding tank
- Water testing kit
- Thermometer
- Aquarium heater
- Air stones
- Small fluorescent light
- Large plastic bucket
- Rotifers
- Rotifer food
- Siphon hose
Instructions
Preparing for Hatching
Set up a small separate breeding tank (10 gallons will suffice). Fill the breeding tank at least partially with water from the main tank to transfer beneficial bacteria. Install an air stone to provide aeration. Do not install a filter as it will endanger the small fry. Install a low-level fluorescent light in the hood of the aquarium.
Install a thermometer and an aquarium heater in the breeding tank. Monitor the water temperature and maintain a temperature as close to the main tank's as possible. Use a water testing kit to measure the breeding tank's ammonia levels and cycle the tank further if necessary. Adjust the breeding tank pH to match the pH of the main tank.
Prepare a rotifer culture at least one week in advance of hatching. Fill a large bucket with saltwater with the same specific gravity as the rotifer starting kit. Install an air stone and set it to its lowest setting to provide aeration. Add the rotifers to the bucket and slowly add rotifer feed until the water becomes a murky green shade. Add additional feed daily to maintain this color.
Introduce one-third of the rotifers to the breeding tank a day or two before hatching the eggs. Allow the rotifers to grow for at least one week and then separate them from the culture water with a sieve or coffee filter. Introduce the harvested rotifers directly into the breeding tank. Add enough rotifer feed to turn the aquarium a light shade of green (not as green as the culture tank, however) and add additional feed daily.
Transfer the eggs from the main tank to the breeding tank seven to 10 days after being deposited -- hatching is imminent when the eggs become a silver color. Use a watertight container large enough to hold the rock or surface that the eggs are deposited on and fill it with water. Place the egg surface into the container underwater -- the eggs must not be exposed to air. Place the egg surface in the breeding tank near (but not in the bubble range) of the air stone.
Cover the breeding tank in thick blankets to create heavy darkness. Wait at least two hours before uncovering the tank and checking if the eggs have hatched. Repeat the process the next day if the eggs have not hatched.
Caring for Hatched Fry
Introduce additional rotifers into the tank immediately after hatching and at two to three hour intervals for the first four days. Spread the rotifers evenly throughout the tank. Harvest no more than one-third of the cultured rotifers each day to allow the culture to continue reproducing.
Use a siphon to remove any dead, dying or deformed fry from the tank as soon as they are noticed to decrease pollution and reduce competition.
Replace a quarter of the breeding tank water every two days to maintain water quality. Add and remove water gradually to avoid shocking the fry with abrupt temperature or pH changes.
Supply live brine shrimp after the fourth day. Use very young brine shrimp, ideally only hours old and no older than two days. Gradually decrease the rotifer feedings and switch to a diet of brine shrimp and crushed flake by the ninth day. Begin feeding the fry once every four to six hours after phasing out rotifer feedings.
Introduce matured fry into the main tank only after they develop their colors (around the 10th day) and reach a length of at least half an inch. Use a plastic bag or siphon to transfer young clownfish as nets can injure or kill them.